DBClient.TCustomClientDataSet.BeforeApplyUpdates
Contents |
Delphi Information
From DBClient.pas
property BeforeApplyUpdates: TRemoteEvent read FBeforeApplyUpdates write FBeforeApplyUpdates;
Unit: DBClient
Type: event
Visibility: protected
Member Of: TCustomClientDataSet
C++ Information
From DBClient.hpp
__property TRemoteEvent BeforeApplyUpdates;
Unit: DBClient
Type: property
Visibility: protected
Member Of: TCustomClientDataSet
Description
Occurs before the client dataset applies updates to the remote server.
Write a BeforeApplyUpdates event handler to send custom information to the client dataset's provider. BeforeApplyUpdates is part of the mechanism by which a client dataset and a provider communicate information about updates. When working with a provider on a stateless application server, this mechanism allows the client dataset and the provider to communicate persistent state information.
When the application calls the client dataset's ApplyUpdates method, the following events occur:
1.The client dataset receives a BeforeApplyUpdates event, where it can encode custom information into an OleVariant that is passed to the provider as the OwnerData parameter.
2.The provider receives a BeforeApplyUpdates event, where it can respond to or change that information before it applies the updates.
3.The provider applies the updates and receives an OnUpdateError event for any problem records.
4.The provider receives an AfterApplyUpdates event, where it can encode custom information into its OwnerData parameter or respond to information from the BeforeApplyUpdates event handler.
5.The client dataset receives an AfterApplyUpdates event, where it can respond to the custom information returned by the provider's AfterApplyUpdates event handler.